Intended for healthcare professionals

Analysis Personal Paper

Nutritional change is not a simple answer to non-communicable diseases

BMJ 2011; 343 doi: https://doi.org/10.1136/bmj.d5097 (Published 11 August 2011) Cite this as: BMJ 2011;343:d5097

Palm Oil and Saturated Fat are Healthy

The article about Nutritional Change recommends the replacement of
saturated fat such as palm oil with unsaturated fat such as sunflower oil.
This is a serious mistake. Two recent meta analyses (1,2) show saturated
fat to be harmless. A paper in the BMJ (3) shows that replacing saturated
fat with unsaturated fat increases heart disease incidence.

Possible mechanisms by which unsaturated fats are harmful include the
following:

* They create oxidative stress which overwhelms the body's
antioxidants. Free radicals oxidise LDL. Oxidised LDL damages arterial
walls resulting in plaque formation.

* The high ratio of omega 6 to omega 3 fatty acids in most
unsaturated vegetable oil causes increased inflammation and this leads to
the metabolic syndrome.

* Canola oil causes atherosclerosis. It contains erucic acid which is
toxic to humans.

It is true that unsaturated fats can reduce cholesterol levels but
this is of no benefit. A graph of total cholesterol against all cause
mortality is u-shaped with a low point at about 6.0 mmol/l. The reduction
in cholesterol is due to a reduction in large fluffy LDL particles which
are harmless. Small dense LDL particles are increased and these are
harmful. There are increasing rates of cancer as the cholesterol level
falls below 6.0 mmol/l.

Palm oil is widely used in Africa and South America. These regions
have low levels of heart disease. If they converted to sunflower oil as
recommended in this article, they would acquire the high rates of heart
disease seen in North America and Europe.

References:

1. Fats and Fatty Acids in Human Nutrition. Annals of Nutrition and
Metabolism, 2009; 55 (1-3).

2. Siri-Tarino PW, et al. Meta-analysis of prospective cohort studies
evaluating the association of saturated fat with cardiovascular disease Am
J Clin Nutr 13 January 2010 [epub ahead of print].

3. Corn Oil in Treatment of Ischaemic Heart Disease, BMJ, 1965, 1,
1531-1533.

Competing interests: No competing interests

11 September 2011
William T Neville
General Pratitioner
Abbey Road Surgery, 63 Abbey Road, Waltham Cross, Hertfordshire, EN8 7LJ